java.lang.RuntimeException: Unable to start activity ComponentInfo{com.project.bots.playhealth/com.project.bots.playhealth.Stopwatch}: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.project.bots.playhealth/com.project.bots.playhealth.Testing}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
at android.app.ActivityThread.access$700(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4950)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:997)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:764)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.project.bots.playhealth/com.project.bots.playhealth.Testing}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
at android.app.ActivityThread.startActivityNow(ActivityThread.java:1951)
at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:135)
at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:347)
at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:704)
at android.widget.TabHost.setCurrentTab(TabHost.java:368)
at android.widget.TabHost.addTab(TabHost.java:246)
at com.project.bots.playhealth.Stopwatch.setupTabs(Stopwatch.java:52)
at com.project.bots.playhealth.Stopwatch.onCreate(Stopwatch.java:36)
at android.app.Activity.performCreate(Activity.java:5177)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
at android.app.ActivityThread.access$700(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4950)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:997)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:764)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.project.bots.playhealth.Testing.onCreate(Testing.java:82)
at android.app.Activity.performCreate(Activity.java:5177)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
at android.app.ActivityThread.startActivityNow(ActivityThread.java:1951)
at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:135)
at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:347)
at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:704)
at android.widget.TabHost.setCurrentTab(TabHost.java:368)
at android.widget.TabHost.addTab(TabHost.java:246)
at com.project.bots.playhealth.Stopwatch.setupTabs(Stopwatch.java:52)
at com.project.bots.playhealth.Stopwatch.onCreate(Stopwatch.java:36)
at android.app.Activity.performCreate(Activity.java:5177)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
at android.app.ActivityThread.access$700(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4950)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:997)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:764)
at dalvik.system.NativeStart.main(Native Method)
제가 실험하느라 안드로이드 폰만 3개인데, 폰 2개는 정상적으로 잘 되고, 하나는 위의 에러가 뜹니다.
이 오류가 왜 뜨는 걸까요?